1. Technical Field of the Invention
This invention relates to antiperspirant compositions. More particularly, this invention relates to highly effective aluminum-zirconium antiperspirant complexes which are non-irritating to the skin and which are non-damaging to textiles.
2. Background Art
Cosmetic preparations having a perspiration inhibiting or retarding effect are well known, and many chemical compounds capable of preventing or retarding the exudation of perspiration have been used or suggested for use in such preparations. In recent years, complexes comprising aluminum and zirconium have been widely used.
Workers such as Grad in U.S. Pat. No. 2,854,382 (issued Sept. 30, 1958) and Daley in U.S. Pat. No. 2,814,585 (issued Nov. 26, 1957), both of which are incorporated herein by reference, describe the use of aluminum chlorohydroxide and either zirconium oxychloride or zirconyl hydroxychloride in combination with an amino acid as the active component of antiperspirant formulations.
Grad, for example, taught that an active antiperspirant complex comprises three necessary components. The first component is zirconyl hydroxychloride, a complex compound having the empirical formula ZrO(OH)Cl. The second necessary component is aluminum chlorohydroxide, a complex compound having the empirical formula Al.sub.2 (OH).sub.6-r Cl.sub.r wherein r has an average value of from about 0.8 to about 1.2. The third necessary component is a water-soluble neutral amino acid, i.e. an acid wherein the number of amino groups equals the number of carboxyl groups.
Schmitz, in Belgian Pat. No. 153,023 (issued Aug. 4, 1975) incorporated herein by reference, also teaches aluminum-zirconium antiperspirant complexes, but complexes which are somewhat different from those taught by Grad. Like Grad, Schmitz uses aluminum chlorohydroxide having the empirical formula Al.sub.2 (OH).sub.6-r Cl.sub.r, wherein r has an average value of from about 0.8 to about 1.2. Schmitz's complex differs from Grad's in that Schmitz uses a novel zirconium compound having the empirical formula ZrO(OH).sub.2-p Cl.sub.p wherein p has an average value of from about 1.50 to about 1.87. Because its pH is somewhat lower than that of the more common zirconyl hydroxychloride, Schmitz's novel material is sometimes called acid zirconyl hydroxychloride, or acid ZHC. Schmitz's antiperspirant complex comprises from 0.15 to 1.5 parts by weight acid ZHC, 1 part ACH, and from about 0.06 to about 60 parts neutral amino acid such as glycine.
While both Grad and Schmitz teach effective antiperspirant complexes, materials having greater effectiveness are still sought. Further, one important use of antiperspirant complexes is in liquid ("roll-on") cosmetic products. The Schmitz complexes exhibit certain physical instabilities when presented in aqueous preparations which make their use in such products less than optimum. This instability is manifested by an increase in viscosity of the aqueous preparations over relatively short periods of time. In fact, this increase in viscosity has, in some cases, been so dramatic that gels are formed. This instability has limited the practical use of such antiperspirant complexes to preparations wherein the presence of a gel can be tolerated (i.e. creams, powders, etc.).
It is an object of this invention to provide novel aluminum and zirconium complexes which are effective antiperspirant materials (i.e. which are highly effective in inhibiting or retarding the exudation of perspiration) and which are stable in aqueous solution while being non-irritating to skin and non-damaging to textiles, and which do not adversely affect containers.
It is a further object of this invention to provide processes for making the novel antiperspirant complexes of this invention.
It is a still further object of this invention to provide cosmetically attractive antiperspirant preparations comprising the novel antiperspirant complexes of this invention.
Other objects will become readily apparent from a reading of the following detailed disclosure of this invention.